Giuseppe Campani was an Italian optician, astronomer and instrument maker. He was known as the best maker of optical instruments of his age.
Background
Campani was born in 1635, in Castel San Felice, Italy, a member of a peasant family. He had two brothers, Matteo Campani degli Alimeni, a pastor of the church of San Tommaso in Via Parione, and Pier Tommaso, a clockmaker in the Vatican palaces.
Education
Campani left his native village as a youth to obtain an education in Rome. While he was learning the new profession of lens grinding, he simultaneously worked with his two brothers on the invention of a silent night clock.
Career
While learning the new profession of lens grinding, Campani worked with his two brothers, Matteo Campani degli Alimeni and Pier Tommaso, on the invention of a silent night clock. Presented to Pope Alexander VII in 1656, the clock brought Giuseppe into prominence, and he went on to produce lenses and telescopes whose superior workmanship earned him recognition from such patrons as Archduke Ferdinand II of Tuscany, Cardinal Francesco Barberini, and Giovanni Domenico Cassini at the Royal Observatory at Paris.
In 1663-1664 Campani invented the composite lens eyepiece and constructed a telescope with four lenses, consisting of a triple ocular and an objective. In 1664 he developed a lens-grinding machine lathe that could grind and polish lenses without first casting blanks in molds. With it, he produced telescopic instruments of great focal lengths that were widely used. Using his own instruments, Campani made significant astronomical observations of the satellites of Jupiter and of the rings of Saturn in 1664-1665 and published the results. Also interested in the microscope, he developed a screw-barrel type of instrument that could be made of metal or wood and permitted greater precision of adjustment than had previously been possible.
Campani was active in the production of lenses and optical instruments for more than fifty years. Louis XIV of France ordered several long-focus lenses for the astronomer Giovanni Domenico Cassini. With these Cassini found several moons of the planet Saturn, among other discoveries.
After Campani's death on July 28, 1715, the contents of his workshop in Rome were purchased by Pope Benedict XIV for the Istituto delle Scienze at Bologna.